Brake noise and excessive wear in disk brake systems are often attributable to the phenomenon of shielding. Shielding is understood as an axial distortion of the brake disk caused by radial thermal expansion.
Shielding may be reduced considerably by decoupling the friction ring from the brake disk hub. DE 199 31 140 A1, for example, describes the manufacture of a composite cast brake disk made of a hub and a friction ring. A hub is provided in this case with radial retaining bolts and is placed into a casting mold. A casting is then made around the hub in the region of the retaining bolts, and the friction ring is formed. Although in this brake disk there is a separation between hub and friction ring, the radial expansion is limited by the rigid retaining bolts.
DE 195 05 112 A1 describes a method for composite casting for a brake disk. A tooth-shaped metal band is inserted between the hub and friction ring, and a casting is made around the metal band, which is then exposed again. Since the metal band does not bond with the casting, the hub and the friction ring are decoupled after the band is exposed. The disadvantage here is the complicated procedure, and a tight axial fit is difficult to ensure.